‘Some games are so overwhelmingly attractive when they first appear that unhappy children can be entirely swept away in them.’
Photograph: Alamy

When a minister in this government stumbles on a policy that is both popular and good, it’s newsworthy. Matt Hancock, the digital minister, has suggested that schools ban the use of mobile phones by their pupils. Amanda Spielman, the head of Ofsted, agrees. In France, the Macron government has put forward legislation that will ban the use of phones in all primary and middle schools. This removes the matter from the discretion of headteachers. Those who have already purged their playgrounds of screens report few problems. The measure seems entirely straightforward and sensible.

There are three kinds of damage that mobile phones can do in the playground and schools are right to tackle them. The most obvious may be the least serious: some games and apps are so overwhelmingly attractive when they first appear that unhappy children can be entirely swept away in them. Fortnite is the latest craze of this sort. Before that there were birds, variously angry and flappy. All these crazes evaporate in time and are replaced by others. The market is just too rewarding for those who get it right. On the whole, though, these problems are self-regulating. The second problem, which is not of course confined to school hours, is that social networks make bullying and cliquishness easier and perhaps more attractive. They make grownups behave like petulant teenagers and real teenagers have fewer defences against their own worst impulses. Schools are right to try to defend themselves and their pupils against such influences.

The most serious, though, is that the constant interruption and the state of twitchy half-attention promoted by the mobile phone tends to degrade the capacity for sustained attention, which schools need to teach. There is evidence, mentioned by Mr Hancock, that the mere presence of a phone makes it harder to concentrate, even when it is concealed in a bag or container. The expectation of distraction is its own distraction. This isn’t just a matter of listening in lessons. Outside the classroom children are constantly learning – and teaching – important social lessons and they need to do this with their real companions rather than imaginary ones. Real communities are made from people who might not have chosen one another and schools should teach children how to live in them. Paying the tribute of attention to the people around us is part of that.

Yet there are practical difficulties with the idea of a national ban on the French model. It would not be reasonable to expect children not to bring their phones to school at all, when so much social life and practical interaction with parents is coordinated with them. If the phones are stored at school that raises security questions about where they are kept. What would be the sanctions for repeat offenders? These are questions for individual schools and headteachers to decide. If Mr Hancock and Ms Spielman are serious, they should be lobbying for financial support for the schools that must carry out their policy.